SPC Apr 23, 2025 Day 4-8 Severe Weather Outlook

Day 4-8 Outlook

Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0315 AM CDT Wed Apr 23 2025

Valid 261200Z - 011200Z

...DISCUSSION...
...Days 5-7/Sun-Tue -- Great Plains to the Midwest...

Forecast guidance is in good agreement that a deepening upper trough
over the western states will eject eastward across the Plains and
Midwest early next week. Beginning Day 5/Sun, the upper trough will
extend from the central Rockies to the Southwest, with a belt of
strong southeasterly flow emerging over the central/southern High
Plains Sunday night. Surface lee low development is forecast over
the northern/central Plains Sunday afternoon, with the low moving
into SD/NE by Monday morning. Southerly low-level flow will
transport ample moisture northward across the Plains and Mid-MO
Valley on Sunday, with a sharpening dryline extending southward from
western NE into western TX. Some severe potential could develop
along the dryline and near the surface low/triple point. However,
forecast soundings maintain strong capping and any convective
development could be rather sparse. For now, this will preclude
severe probabilities for Day 5/Sun. 

On Day 6/Mon, the upper trough will continue eastward, moving into
the Plains by Tuesday morning. Ahead of the trough, a belt of strong
southwesterly flow aloft will extend from OK into the Upper Midwest.
A deepening surface low over SD will shift east/northeast through
the period, with a trailing cold front shifting east/southeast
across the Plains. Rich boundary layer moisture within a moderate to
strongly unstable airmass and favorable shear parameter space will
support an all-hazards severe weather episode across a fairly broad
area from OK to MN/WI Monday afternoon into Monday night.

Severe potential is likely to continue into Day 7/Tue, though some
differences within medium range guidance with the evolution of the
upper trough and key surface features does result in a bit more
uncertainty compared to Monday, especially on the eastward extent of
severe potential. Nevertheless, strong forcing atop a broad warm
sector ahead of an eastward advancing cold front will continue to
support severe potential from northeast Texas into Lower MI.

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